1. Field of the Invention
The present invention relates to an electric vehicle having a ground fault detecting system for detecting a ground fault or an insulated state of an ungrounded power supply with respect to a grounded region (ground) of the electric vehicle.
2. Description of the Related Art
Generally, electric vehicles carry a power supply having a high voltage, which is of 200 [V] or higher, for example, insulated from the vehicle body as an ungrounded power supply.
There have been proposed technologies for detecting a ground fault (including a ground leakage or a lowered insulation resistance value due to a deteriorated insulation) of such a high-voltage ungrounded power supply (see, for example, Japanese Laid-Open Patent Publication No. 08-226950, Japanese Laid-Open Patent Publication No. 08-070503, and Japanese Laid-Open Patent Publication No. 11-218554).
According to the technology disclosed in Japanese Laid-Open Patent Publication No. 08-226950, a ground fault of a single ungrounded power supply is detected and determined by a DC ground fault detecting system.
According to the technologies disclosed in Japanese Laid-Open Patent Publication No. 08-070503 and Japanese Laid-Open Patent Publication No. 11-218554, a ground fault of a single ungrounded power supply is detected and determined by an AC ground fault detecting system.
Nowadays, there have been proposed electric vehicles which have a load energizable by a first ungrounded power supply such as a fuel cell and a second ungrounded power supply such as an electric energy storage, e.g., a battery or the like. However, no ground fault detecting system has been known in the art for use on such electric vehicles including first and second ungrounded power supplies.